Freshly chopped firewood has up to 50% water content and won't burn in your fireplace. First, you must let the firewood season (dry), which allows the moisture to escape––the drier the wood, the cleaner the burn. When the wood gets down below 22% water content, it's ready to burn. Burning unseasoned (green) or even partially seasoned wood in your stove or fireplace will cause creosote build-up in your chimney, which can lead to a chimney fire at the worst, and a lack of fire or a roomful or smoke at best.